Curcumin is a non-toxic, stable phenolic substance, which is mainly utilized as a common natural food coloring agent in daily life. Currently, curcumin is extracted by various methods and processes, such as antisolvent supercritical method, liquid-liquid microextraction, ultrasound-assisted ionic Soxhlet extraction, and so on. In addition, curcumin has antioxidant, anti-inflammatory and antiviral properties, can treat metabolic and neurological disorders, and has a regulatory effect on intestinal flora. In particular, curcumin has antioxidant capacity mainly related to the structure of the β-diketone of the curcumin molecule and increases the performance of several antioxidant enzymes, which in turn reduces lipid peroxidation, decreases liver damage, and prevents the onset of carcinogenic processes. Curcumin modulates and interacts with a variety of molecular targets, and these mechanisms of action are essential for neuroprotection. Curcumin has the ability to increase levels of plasma insulin and activity of hepatic glucokinase, reduce the actions of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, which in turn decreases glycosylated hemoglobin levels and blood glucose and increases glucose tolerance in vivo. By increasing the diversity of intestinal flora, curcumin is capable of changing the ratio of pathogenic and probiotic bacteria in the intestinal tract, protecting human intestinal health.